Steam-engine.



J. STUMPF.

STEAM ENGINE.

APPLICATION FILED MAYH. 1914.

1,201,383. Pdtented 001. 17, 1916.

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IIIIII/II WITNESSES INVENTOR M W QQW HM ATTORNEY.

J. STUMPF.

STEAM ENGINE.

APPLICATION FILED MAY 4. 1914.

1 ,201 ,383 Patented Oct. 17, 1916.

3 SHEETS-SHEET 2.

O 0 [EE llVVE/VTOI? MM W B) Q a ATTORNEY.

J. STUMPF.

STEAM ENGINEP APPLICATION FILED MAY 14. 1914.

Patented Oct. 17, 1916.

3 SHEETSSHEET 3- t 444 n ATTORNEY.

.a STATES PATENT omen 10am s'rmr, or'nnnnm, GEBEAITY.

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v Specification o1 Letters-Patent. Patented Oct. 17, 1916;

Application filed Hay'14, 1914. 'serial' no. 838,482.

To all whom it may concern:

Be it known that I, JOHANN STUMPF, a subject of theEmperor of Germany, residing in Berlin,WV., Germany, have invented a new and useful Improvement in Steam- -Engines, of which the following is a specification.

This invention relates to improvementsin soon as the driving steam is shut oil.

. The object is also to eliminate the necessity for providing a large clearance volume with large surfaces, which involve loss, for the introduction of the large quantity of compression steam ordinarily required.

Referring to the drawings, which illustrate merely by way of example, a suitable embodiment of my invention-Fig'ure 1 is a partial longitudinal section of a locomotive "cylinder of the una-fiow'type. Fig. 2 is a yertical section through the locomotive cylinder with the main valve gear in modified form. Fig. 3 is a plan and part horizontal section of arrangements shown in Fig, 2. 1 Similar numerals refer to similar parts throughout thesevcra'l views.

The attempt has already been made to devise an arrangement for coasting'in mountain work on locomotives built on the unaflow principle, in that both inlet valves have been opened and held open by the valve gear.

The contents of the cylinder would then be' pushed back and forth by the piston through the open inlet valves and the common steam chest. With this arrangement a special design of gear and a special setting of the samefor coasting was necessary.

According to the present invention the outlet valves Will'be placed near the ends of the cylinder and illcommunication therewith. These outlets may cotiperate with another exhaust valve gear; such, for example,

as an exhaust port arrangement provided with the; usual exhaust pipe.- These' outlet cordingi' v valves are controlled in a well known man- Iier by the excess of pressure-in the cylinder on one side and a spring on the other, so that they open and close automatically actO the internal pressure. remaining open henever atmospheric or higher exhaust pressure,'as the case may'be, prevails in theicylinder. The contents of the cylinder will then be forced toand fro through these outlet valves and their common pa s-' sagesbythe piston. The common exhaust passage on non-condensing engines may be arranged w th a special valve operated in any convenient manner to put the exhaust 'passage near the cylinder in communication with the atmosphere. This makes possible a renewal and a cooling-of the contentsof the cylinder.

' The arrangement is of first importance for locomotives, which must run idle'or coast for long periods; but is of significance in the case of statlonary engines in that it may avoid the compression and the friction and pulsations of the engine ,When the live steam 1s shut off. Portable (locomobile) engines as well as locomotives are at a disadvantage.

in that cinders or at least smoke etc. is sucked back into the cylinders, which is done away with by the new arrangement.

The running arrangement as an example is shown in Fig.; 1. The inlet valve gear, which is without interest for this invention, consistsof valves 5:moved by means of a roller and cam as clearly explained in my Patent No. 1,042,168; Oct. 22, 1912, are situate-in the cover'7, of the cylinder 6. The principal outlet takes place through the well known port openings 8 in the middle of the cylinder controlled by means of the working piston 9.

In the vicinity of the ends of the cylinder are arranged outlet valves 10. Each spindle 11 of the valve 10 extends outward through a housing 12 in which an opening spring 13 works upon the same. In the vicinity of the valve 10 the spindle 11 carries a piston 15 which moves in a shallow cylinder 17 on the outer cylinder wall. The underside of this piston 15 is in free communication with the common exhaust passage 19 from the auxiliary valves 10. Above the piston 15 each cylinder 17 is in direct communication with the inside of the working cylinder 6 stroke.

, with an air pressure supply at one end and at the other end with a cylinder containing piston 26. Piston 26 is mounted on the spindle of the valve 23, so that the, valve 23 maybe opened by means of air, pressure during long coasting.

The operation is as follows: During compression and admission the auxiliary valve 10, which remains closed onthe side in question, since increasing. pressure on the outside of the valve piston 15 through the pipe 20 overcomes the pressure of the open- .ing spring 13. WVith considerable fall of pressure in the cylinder, duringexpansion and exhaust, the pressure of spring 13 prevails so that valve 10 opens. During the compression stroke of the piston the valve 10 remains open until the piston has closed the passage 10 leading from the auxiliary valve to the cylinder. 9 valve follows the compression of the remaining' steam and the entrance of fresh steam because pressure through the pipe 20 prevails on the auxiliary cylinder 17. If the supply of steam is shut off, either'the valves 10 remain full open, or, they close as a result of the compression pressure when the piston has nearly reached the end of its They open immediately, however, with the returning'stroke of. the piston, at the latest when the backward movement of the piston opens passage 5, and the contents of the cylinder will be forced back and forth through the open valves-10 and the passage 19, the opening of the central valve 23 also removing a tendency to vacuum. If the ad-, mission valves are partly throttled a smaller 4 compression will result, because, in coasting, the live steam-is shut off. The faults in steam distribution of a link-gear valve are exhaust too far in advance of the end of the stroke, too high compression, and too severe throttlingwith short admission. If the exhaust lap of the central position of the link gear gives theoretically a compression beginning at 50% stroke, as a result throtstroke. Froin this arises the necessity of providing a large clearance volume with large surfaces, which involve loss, for theintroduction of the large quantity of compression steam, so for example, locomotives must have on these grounds according to the initial pressure an injurious clearance chamber of 12 to 14%. The valve gear of stationary engines operated by a movable eccentric and controlled by a shaft governor behaves in the same way as the link gear on locomotives. I avoid these defects b adding to the main valve gear a second out etorgan operated independently by steam pressure. Fur- The closure of the- Leone be controlled by the main valve gear,'or the link gear of a'locomotive, from the main 'main valve gear, the important considera-'- .tion enters that the exhaust lap may be greatly increased,- so that with cut 0H at 10%, exhaust'will begin at 15% before the end of the stroke orless. This amount of exhaustxreturns to a normal amount with a longer admission.

The arrangement which is. shown by way of example in Figs. 2. and 3, is designed in .valve are placed two auxiliary valves 33 which control the passage 34 somewhat removed from the'cylinder end. Each valve 31 ,is designed in piston form as at 33 and the ring shaped passage 57 of each valve is connected through a pipe 54; with the passage 32, where the pipe enters through the opening 56. On the concave side of the piston web 33 each'valve 33 is loaded by a spring 37. The valve rod carries a housing 53 in which a double acting oil' dash-pot is formed with the piston shaped end of the spindle-52.

' When the main valve 31 admits live steam into the cylinder, it also admits live steam at the same time by way of 56, 54 into the annular space 57 of the second valve 33. The steam pressure overcomes the pressure of the spring 37 and-closes the valve. \Vith the following for-ward travel of the piston the corresponding valve 31 is closed as soon as the connecting passage 3+ is opened by the piston. After closureot the main valve, expansion begins, until the piston uncovers the second passage 31 at the opposite end of the cylinder. The valve 33 belonging to this end is open. Exhaust therefrom followsthe uncovering of this port or passage 34. Previously with short admission (early out oif) exhaust would have already taken place through the main valve. Vith longer admission (later cut off) the main valve holds the outlet still closed, so that exhaust ther, the steam-entrance to the second outis limited by the second valve. The exhaust let valve loaded on one side by a sp'ringgw'ill takes place through two openings. At. the

. entirely by the auxiliary valve.

the old link gear.

same time-atthe-first end of the cylinder the live steam is released from. the annular space 57 whereupon the closing spring opens the opposite outlet valve 33. The returning piston forces the steam out .of the cylinder through the main and auxiliary outlet valves. Compression can begin only when the piston hasv overrun the proper passage 34.

Full freedom of adjustmentof the lap of the auxiliary valves which depend upon valve 33 according to the lap of the main valve for control otthe passage 32 is allowed. For example, the exhaust lapmay be made so large that exhaust is limited According to the drawings there would be a constant compression of 17 and an exhaust'of 15% of the stroke (with admission of 10%) which would decrease with increased admis- 'sion until it was held by the action of the valve 33 at a 'value of about 6%. As a result of the small volume compressed there is a total volume for clearance losses of.

about 5% as contrasted with the 14% of T hrou gli the reduction of clearance volumes with superheated steam areduction of steam consumption is obtained which amounts to a inean value of .6 kg. per H. 1 hour. large part of the cooled exhaust steam escapes from the cylinder by way of the auxiliary passages, so that the cooling down of' the admission surfaces of the cylinder is in large part avoided. From this results still further conquest over surface losses. Further, a gain in diagram area ,is achieved from the reduction of exhaust and c'ompres sion. By the arrangement" described, the special outlet passage 3% so adjusts the compression that itgives the utmost reduction.

of clearance losses under norm -al operation. With the assistance of the new valve gear a reduction of steam consumption with superheat of 1 to 1.2 kg. per H. P. hour, compared to the known arrangements may be achieved. \Vith saturated steam the gain is actually still greater. 1

,It during'coasting of the locomotive the driving steam is shut off, both of the springs 37 hold open the outlet valves 33, and a transfer between the cylinder ends, which may be connected withthe atmosphere by means of a special check valve, is so ar ranged as to prevent the rise of temperature due to the oscillation of the contents of the cylinder.

The auxiliary passages 34 may be located at the same position as the main valve passages 32 in order to reduce still further the clearance losses. Compression is then controlled not by the overrunnmg of the auxiliary outletpassages bythe piston, but by the action of the valve 33alone. The oil dashppts of the valves 33 limit the extremes Furthermore, a.

of the strokes and assure noiseless opfira'tion. Ineach dash pot is arranged a suitable ring valve which prevents formation of a vacuum. "At the same time the oil dash 'pot provides lubrication for the valve are still further helped by the ample movement of the auxiliary valve which pumps from end position to end position very P quickly during dead center, While time is given without involving undesirable throttling. For example, the auxiliary outlet valve is fully opened on dead center, while at the same time, before the dead center, the

other auxiliaryoutlet valve acted together with the main outlet (exhaust) motion. The closure of the auxiliary valve follows immediately after the piston has closed the auxiliary outlet port.. All difficulties with throttling are therefore lacking here.

In place off the auxiliary main valves, any kind of valves and motion may be used, only the me hod of operating the valve gear is important. The actual design or construction of the valve gear does not matter. The auxiliary outlet valves might be operated by a connection with the corresponding end of the cylinder instead of by a special port covering of the main valve. Also a special governingvalve might be used for operating the auxiliary outlet valves.

iy allowing free running for down grade the auxiliary outlet valves at the same time remove the additional clearance surt aces and volume losses which are connected with the introduction of a special by pass valve.

lnsteadof operating the auxiliary outlet valves with the aid of auxiliary springs,

some. other constant forcesucll as steam or air pressure may be used to control the auxiliary exhaust mechanism. auxiliary exhaust valves could be controlled without the help of a constant-force by the arrangement of two pressure chambers. in such a way that each chamber is in communication with that end of the main valve proper to the corresponding end of the cylinder.

\Vith the above described method of operation. both the danger of sucking in of impurities and the cuttiugof the cylinder, with further cooliug 0d. are prevented. If the link gear is reversed, the outlet valves Also the also automatically reverse and always work having main and auxiliary exhaust ports, a

as if the link gear valve were entirely laid out? The reversal would take place without anyl-chance of a parti'cularlink gear as a result of the indire'ctdependence upon the main valve'motion, and the throttling difv ficulties which would otherwise be present with a link gear valve motion are completely avoided.

What I claim .is:- I a 1. In combination with an engine cylinder piston operating therein, having piston rings on the hot end thereof which overrun the auxiliary exhaust port, a common outlet pas sage, automatically operated outlet valves near the cylinder ends, communicating with the common outlet passage, and valve controlling means sub ect to the steam pres-' sure of the cylinder, whereby the valves open, when the steam supply is cut oil.

2. In combination with an engine-cylinder, a common outlet passage, automatically operated outlet valves near the cylinder ends, communicating with the commonout-' let passage, and valve controlling means subject to the steam pressure of the cylinder,

whereby the valves open, when the steam supply is cut off to establish communication between the inside of thecylinder on both I sides of the working piston.

3. In combination with an engine 'cylinder having main and auxiliary exhaust ports, a piston operating therein, having piston rings onv the hot end thereof'which overrun the auxiliary exhaust port, a common outlet passage, automatically operated outlet valves near the cylinder ends, communicating with the common outlet passage, and valve 'controlllng means subject to the steam pressure of the cylinder, whereby the valves open, when the steam supply is cut oil, and a mechanically controlled check -val.ve for controlling communication bepressure of the cylinder, whereby the valves open, when the steam supply. is cutoff, and

tween the connnonpassage and the atmos-.

phere. I

4. In combination with an engine cylinder having main and auxiliaryexhaust ports, a piston operating therein, having piston rings on the hot end thereof which overrun' the auxiliary exhaust port, a common outlet passage, automaticallyoaerated out.- let valves near the cylinder ent s, communicating with the common outlet passage, and valve controlling means subject to the steam a mechanically controlled check valve for controlling communication between the common passage aptl the exhaustchamber,

5; In combination with a. una-directional flow engine cylinder having main and auxiliary exhaust ports, apiston operating therein, having piston rings on the hot end thereof which overrun the auxiliary exhaust port, a common outlet passage, outlet ports midway the cylinder ends communicating with said passage, automatically operated outlet valves near the cylinder ends also communicating with said common passage, controlling means for said valves, sub ect to the steam pressure of the cylinder, for open- -ingthe valves when the steam supply is cut oil.

6. In combination with a una-directional flow engine cylinder ha-ving main and auxiliary exhaust ports, a piston operating the rein, having piston rings on the hot end thereof which overrun'the auxiliary exhaust port, an outlet passage, outlet ports midway the cylinder ends communicating with said passage, automatically'operated outlet valves near the cylinder ends, controlling means for said valves, subject to the steam pressure of the cylinder, for openin the valves when the steam supply is cut 0 as means whereby both ends of the cylinder areput into communication with each other. I

7; In combination with a Lina-directional flow engine cylinder having main and auxiliary exhaust ports, a ,pistonoperating therein, having piston rings on the hot end thereof-which overrun the auxiliary exhaust through the common passage, and 'a;me

chanically' operated controlling valve for said common outlet passage.

.8. An engine cylinder having exhaust ports in the cylinder wall to be uncovered by the piston at or near the end of its working stroke, a passage communicating with the exhaust ports, automatically operated outlet valves near the cylinder .endsv commun1cat-' ing with the free atmosphere, and valve controlling means subject to the-steam pressure of the cylinder, whereby the valves open when the steam. supplyis cut otf;

9. In a steam engine, the combination of a cylinder and a piston working therein, the cylinder having exhaust ports :ulapl'ed to be uncovered by thepiston at-or near the end of its stroke and an auxiliary exhaust port near the cylinder end, a valve'for controlling said auxlharyexhaust port operated by the steam pressure in one direction and spring pressure in the other, thepiston having piston rings on-the hot end thereof \VhlCll overrun the auxiliary exhaust port.

10. In a steam engine, the combination of a cylinder and a piston working therein, the

cylinder having exhaust ports adapted to be uncovered by the piston at or. near the end of its stroke, an auxiliary exhaust port near the cylinder end and a valve for controlling said auxiliary exhaust port adapted to be maintained in the closed position against a counteracting force by steam1 pressure, the

piston having piston rings on the hot end thereof which overrun the auxiliary exhaust ort. e r

p 11. In a steam engine, thecombination of a cylinder and a piston working therein, the

cylinder having exhaust ports-adapted to be uncovered by the piston .at or near the end of its stroke, an auxiliary exhaust port near the cylinder end and a valve for controlling said auxiliary exhaust port, adapted to be maintained in the closed position against a counteracting force by the pressure in the cylinder,"t-he piston having piston rings on the hot end thereof which overrun the auxiliary exhaust port.

12. In a steam engine, the combination of a'cylinder and a piston working therein, the cylinder having exhaust ports adapted to be uncovered by the piston at or near the end of its stroke, an auxiliary exhaust port near the cylinder end and a valve for controlling said auxiliary exhaust port, adapted to beexhaust valve open and means operated by the pressure of the live steam for closingthe exhaust valve, the piston having piston rings on the hot end thereof which overrun the auxiliary exhaust port.

14. The combination of a steam engine cylinder and a piston working therein, the cylinder having a valve controlled inlet and a valve controlled exhaust at or near the end thereof, means for normally maintaining the exhaust valve open and means operated by the pressure of the live steam controlled by the inlet valve for closing the exhaust valve, the piston having piston rings on. the hot end thereof which overrun the auxiliary exhaust port. 15. The combination of a steam eng'in cylinder and a piston working therein, the cylinder having a valve controlled inlet and -a valve controlled exhaust at or near the end thereof, means'for normall maintaining the exhaust valve open an means 'operated by the pressure of the live steam admitted to the cylinder for closing the exhaust valve, 'the piston having piston rings on the hot end thereof which overrun the.

auxiliary exhaust port.

16. A steam engine cylinder and a piston working therein, the cylinder having inlet ports and exhaust ports and valves for controlling the same, the exhaust port valve adapted to be opened by a spring and closed by the pressure of live' steamwhich is con trolled by the'inlet valve, whereby when the live steam is cut off for coasting, the ex haust valves open, the piston having piston rings-onvthe hot end. thereof which overrun the auxiliary exhaust port. l

17. A steam engine cylinder and a piston working therein, the cylinder having inlet and exhaust ports, valves for controlling the same, the exhaust port valve adapted to' be opened by a spring and closed by the pressure of the steam, which pressure is controlled by the inlet valve, and a suitable valve opening to atmosphere the exhaust,-

spaces or passages, whereby when'the live steam is out 01f for coasting, the exhaust valves remain open and a tendency to vacuum prevented, the piston having pistonrings on the hot end thereof which overrun the auxiliary exhaust port.

18. In combination with a steam engine having a main cylinder andpower piston' working therein, auxiliary exhaust valve organism comprising a cylinder and piston element, means for leading the live steam thereto to act upon the piston element against a counteracting force, and means whereby the steam inlet valve controls the admission of live steam to said piston and piston element, the power-piston having piston rings on the hot end thereof which overrun the auxiliary exhaust port.

19. In combination with a steam engine I cylinder and a power piston workiiigtherein, an auxiliary exhaust valve organism com prising a cylinder and a piston element op-' erating therein,means for establishing communication between said cylinder and piston element, and the head of the engine cylinder, whereby the pressure of the engine cylinder is utilized to actuate the piston element to close the exhaust valve against a counteracting force, the power piston having piston rings on the hot end thereof'which overrun the auxiliary exhaust port.

20. In a steam engine, the combination of a double acting cylinder and a piston working therein, the cylinder, having exhaust ports adapted to be uncovered by the piston at or near the end of its stroke and an auxil-- iary exhaust port-near the cylinder'end, a valve for controlling said auxiliary exhaust port operated by the steam pressure in one direction and spring pressure in the other,

the piston having piston rings on the hot' end thereof which overrun the auxiliary exhausls port. a

21. In a steam engine, the combination of a double acting unaflow cylinder and a piston working therein, the cylinder having exhaust ports adapted to be uncovered by the piston at or near the end of its stroke and an auxiliary exhaust port near the cylinder end, a valve for controllingsaid auxiliary port operated by the steam pnessure in one 10 direction and spring pressure 1n the other, the plston having piston rings on the hot end thereof which overrun the auxiliary ex- 

